Rainwater entering boiler flue causing internal leak

[genki1]

Hi,
Looking for some advice from the wonderful experts on this forum!

I've been experiencing rainwater entering my boiler via the flue on my back wall (pictured) and dripping down through the boiler and then causing damage to internal walls. Sadly, there is only one downpipe on the row of terraced houses that I live on, which belongs to next door. Due to the build up of debris and the fact it takes water from 5 terraced houses, the gutter often overflows in heavy rain, which then drips directly onto and into my flue. I cannot afford to move the boiler, so was wondering what the best solution might be. I've considered a boiler plume diverter kit? Or a boiler flue cover installed above? Obviously, we can keep trying to clear out the gutters, but this is not a long term solution and there is no possibility of installing additional downpipes at the back. I cannot do this as my lean to conservatory (installed before I moved in, as was the boiler) spans the whole of the back of the house.

Thanks so much in advance for your ideas.

 

[Wayners]

Move the down pipe outlet further to the right to start with. Get it away from flue

 

[fixitflav]

Move the down pipe outlet further to the right to start with. Get it away from flue

Before that, make sure the down pipe is not blocked. Then the gutter might not overflow.